The present disclosure relates generally to patient access disconnection systems and methods for medical treatments. More specifically, the present disclosure relates to the detection of patient access disconnection, such as dislodgment of a patient access device during medical treatments or therapies including dialysis therapy.
A variety of different medical treatments relate to the delivery of fluid to and/or from a patient, such as the delivery of blood between a patient and an extracorporeal system connected to the patient via a needle or needles or any suitable access device inserted within the patient. For example, hemodialysis, hemofiltration and hemodiafiltration are all treatments that remove waste, toxins and excess water directly from the patient's blood. During these treatments, the patient is connected to an extracoporeal machine, and the patient's blood is pumped through the machine. Waste, toxins and excess water are removed from the patient's blood, and the blood is infused back into the patient. Needles or other suitable access devices are inserted into the patient's vascular access in order to transfer the patient's blood to and from the extracoporeal machine. Traditional hemodialysis, hemofiltration and hemodiafiltration treatments can last several hours and are generally performed in a treatment center about three to four times per week.
During any of these blood treatments, dislodgment of the access device can occur, such as dislodgment of a needle inserted into the patient's vascular access including an arterio-venous graft or fistula. If not detected immediately, this can produce a significant amount of blood loss to the patient. The risks associated with a needle dislodgment are considerable. Important criteria for monitoring blood loss include, for example, the sensitivity, specificity and response time with respect to the detection of needle dislodgment. With increased levels of sensitivity, specificity, and response time, the detection of needle dislodgment can be enhanced, and blood loss due to dislodgment can be minimized.
Typically, patients undergoing medical treatment, such as hemodialysis, hemofiltration or hemodiafiltration, are visually monitored in order to detect needle dislodgment. However, the needle may not be in plain view of the patient or medical staff (i.e., it may be covered by a blanket) such that it could delay detection and, thus, responsive actions to be taken in view of dislodgment, such as stopping the blood pump of the extracorporeal machine to minimize blood loss to the patient.
Moreover, in view of the increased quality of life, observed reductions in both morbidity and mortality and lower costs than in-center treatments, a renewed interest has arisen for self care and home hemodialysis therapies. Such home hemodialysis therapies (whether hemodialysis, hemofiltration or hemodiafiltration) allow for both nocturnal as well as daily treatments. During these self care and home hemodialysis sessions, especially during a nocturnal home hemodialysis session, when the patient is asleep, dislodgment risks are more significant because nurses or other attendants are not present to detect the dislodgment.
A need exists to make an access disconnection (“ADS”) system operate as quickly as possible to minimize blood loss.
A need also exists to make the ADS system operate to without false triggers, which needlessly disrupt therapy and the patient.
A further need exists to provide such an ADS system readily and relatively inexpensively to machines already in use which may not have an ADS system or one that operate as well as the systems described herein.